Furnace-wall



E. BERNITZ.

FURNACE WALL.

APPLICATION FILED Mo: 12. 1916.

1,393,696, Patented Oct. 11, 1921.

Snow J01,

- attotueq UNITED STATES ERNEST BERNITZ, OF BOSTON, MASSACHUSETTS,

ATENT OFFICE.

ASSIGNOR TO BERNITZ FURNACE cnusnzrrs.

FURNACE-WALL.-

Specification of Letters Patent.

Patented oct. 11, 1921.

Application filed December 12, 1916. Serial No. 136,535.

To all whom it may concern:

Be it known that I, ERNEST BERNITZ, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in F urnace-Walls, of which the following is a specification.

My said invention relates to furnace wall construction and consists in. the combinations and arrangements of elements hereinafter described and particularly set forth in the accompanying claims.

The invention has for its purpose to construct the walls of a furnace in a manner which will admit air to the fuel bed and insure the proper and complete combustion of the fuel and prevent the wearing away of the fire-bricks by fusion when the maximum temperature is reached, with its consequent lessening of the efliciency of the plant and expense in reconstruction.

In furnaces for water-tube boilers where the fuel is supplied by underfeed stokers and forced draft is employed, the heat in the fuel-bed becomes so intense that at times the melting point ofthe fire-bricks, or other wall' structure, is reached, when the wall or fire-bricks become soft and fuse with the clinkers and ashes, and this fusion'wears away the walls at this region of the furnace. Also, when this clinker mass is broken away, an adhering portion of the wall is usually taken, and thereby the furnace wall structure is undermined at the bottom, and this ultimately causes a total collapse of the structure, or necessitates the frequent drawing of the fires for repairing the de teriorated parts of the fire-brick walls.

Now, to overcome these serious defects, it is proposed to admit air into the fuel-bed at points where the greatest clinker formation occurs and to aid combustion by supplying air to the coal where clinkers and ashes have heretofore obstructed the openings in the grates. And it is further proposed to provide an arrangement for admitting the air into the fire-place through graduated series of openings to the end that the supplied air will reach the fuel-bed in amounts commensurate with the intensities of the heat in different regions of the firebed.

The invention is shown by way of illussald valve is tration in the accompanying. drawings, wherein- V Figure 1 is a longitudinal section ofa furnace showing the application of the present invention thereto.

Fig. 2 a transverse sectional view thereof taken on the line 2-2 of Fig. l, and

Fig. 3 shows a modified construction of wall that may be used.

Referring to the construction in further detail wherein like reference characters indicate corresponding .parts in the several views, 1 designates the front wall of'a furnace preferably of the underfeed stoker type, 2 the side walls thereof (one being shown), 3 the bridge wall, 4 the side wall arch, and 5 the fire door, all constructed in accordance with the well-known type of furnaces employed in water-tube boilers where the fuel is supplied by underfeed stokers and forced draft.

The furnace construction per .96 further includes the dumping grate 6 and the twyer box 7 providing the channel-way 9 beneath the fire-bed, which channel-way communicates with the flue 10 from the source of air supply above atmospheric pressure.

The present. invention proposes to admit air into the fuel-bed in amounts commensurate with the varying intensities of flame therein, 2'. e., into the fuel-bed direct as distinct from above the surface of the fuelbed, which is a well-known practice in the instant art.

To these ends, a slide valve 11 ismounted in guide-ways 12 to control an opening through the side plate of the twyer box, and

provided with a hand manipulating rod 13 located conveniently adjacent the furnace door for controlling the amount of air admitted into the fire-bad, as will be understood. The passage 11", controlled by said valve 11, communicates with a space or chamber 16 formed in each side wall of the furnace, and from said chamber-the air is admitted into the fuel bed through a series of openings 15 that are of increasing cross section downwardly toward the medial horizontal plane of the fire-bed, and of decreasing cross section below said plane, to the end that the air will be admitted into the fire-bed in a manner which will prevent the formation of clinker bodies. As heretofore such as shown in Fig. 3, where the air apertures are formed by passageways 22 in the bricks 21. In the construction, the furnace wall adjacent the air chamber 16 is reinforced by a series of spacing and supportin bricks 17, suitably set therein.

lhe bridge wall 3 is in like manner provided with a space 18, communicating with the twyer box and having openings 19 for feeding the air into the fuel-bed. A valve 20 is suitably located to control the supply of air to the passage 18 and is controllable from a convenient posit-ion outside.

The purpose of the invention and its manner of operation may thus be summarized: Air above atmospheric pressure circulates through the furnace walls and discharges from openings in said walls into the fire-bed where the fire is hottest, and thereby prevents the formation of clinkers. Also the walls of the furnace at these regions are prevented from excessive expansion and contraction, which otherwise would naturally cause the walls to shatter or deteriorate.

-It is obvious that those skilled in the art may vary the details of construction and arrangement of parts without departing from the spirit of my invention, and therefore I do not wish to be limited to such details except as required by the claims.

Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent, is:

1. A furnace wall constructed of firebricks and having an air passage-way therein, and said bricks on the inner side of said passage-way spaced apart providing a plurality of alr ducts leading from said passage-way into and below the surface of the fuel bed, said ducts being of successively increasing cross section downwardly toward the medial horizontal plane of the fire-bed and of successively decreasing cross section below said plane, substantially as set forth.

2. An underfeed stoker furnace having walls constructed of fire-bricks and adapted to be supplied with air under forced draft, said walls having passage-ways therein, and said bricks on the inner side of said passage-ways spaced apart providing a plurality of air ducts leading from said passage-ways into and below the surface of the fuel bed, said ducts being of successively increasing cross section downwardly toward the medial horizontal plane of the fire-bed and of successively decreasing cross sect-ion below said plane, substantially as set forth.

3. A furnace wall constructed of fire bricks only, provided with an air passageway in said wall, with the fire bricks on the inner side of said passageway forming the furnace wall face, and said wall face bricks being spaced apart, forming a plurality of air ducts leading from said passageway into and below the surface of the fuel bed, at the sides, means to supply forced draft to said passageway, whereby a constant supply of cool air under pressure will be forced into the fuel, through the brick in said furnace walls and prevent the formation of clinkers on said brick, substantially as set forth.

4. Furnace construction of fire brick consisting in providing the side brick walls of the furnace with an air passageway immediately back of the brick constituting the face of the furnace wall, setting said furnace wall brick spaced to provide a plurality of air ducts from said passageway through the wall into the furnace chamber below the level of the fuel bed, in combination with meansto supply air under forced draft to said passageway and through the spaced furnace wall brick into the fuel bed, whereby the face brick are preserved, maintained and protected from burning out, and the formation of clinkers on the fire brick is eliminated. I

5. Furnace construction of fire brick consisting in providing the side and bridge brick walls of the furnace with an air passageway immediately back of the brick constituting the face of the furnace wall, setting said furnace wall brick spaced to providea plurality of air ducts from said passageway through the wall into the furnace chamber below the level of the fuel bed, in combination with means to supply air under forced draft to said passageway, and through the spaced furnace wall brick into the fuel bed, whereby the face brick are preserved, maintained and protected from burning out, and the formation of clinkers on the fire brick is eliminated.

6. Furnace construction of fire brick consisting in providing the side and bridge brick walls of the furnace with an air passageway immediately back of the brick constituting the face of the furnace wall, setting said furnace wall brick spaced to provide a plurality of air ducts from said-passageway through the wall into the furnace chamber below the level of the fuel bed, an air duct communicating with said passageways, a source of forced draft Supply, and means to conduct cool air under pressure through said air passageways and into the side and brick furnace walls below the sur- 7. In a furnace for sustamed operation athigh temperatures, a fuel support, fixed slde' walls for laterally confining the fuel on the support,- saidwalls being made of non-metallic refractory material with fuel contacting faces of said material havin a multipllcity of apertures therethrough 1n the fuel confining-area, and with interior air supply passages formed entirely by the non-metallic refractory material ofsaid walls and 'communicating with said apertures, and means for supplying relatively cool air under pressure to said passages and apertures whereby said air will be forced under pressure into the body of supported and confined fuel through the fuel confining faces, and said faces will be preserved and the formation thereon of clinkers prevented, substantially as described; e

8. In a furnace for sustained operation at high temperatures, a fuel support, fixed. walls for confining the fuel on the support,

said walls being made of non-metallic refractory material with fuel contacting faces of said material having a multiplicity of apertures therethrough in the fuel confining area, and with interior air supply passages formed entirely by the non-metallic refractory material of said walls and communicating with said apertures, and means for supplyingrelatively cool air under pressure to said passages and apertures whereby said air will be forced under pressure into the body of supported and confined fuel through the fuel confining faces, and said faces will be preserved and the formation thereon of clinkers prevented, substantially as described.

In testimony whereof I aflix my signature in the presence of two witnesses.

v ERNEST BERNITZ. Witnesses:

OSCAR 0. NYGAARD, JOHN Gnossman; 

